Bush A.,Imperial College |
Bush A.,U.S. National Institutes of Health
Paediatric Respiratory Reviews | Year: 2015
Leukotriene receptor antagonists were introduced as an entirely new concept in asthma therapy, which indeed they are. However, although an intellectually new concept, they have largely disappointed in clinical practice. A small minority of school age asthmatics may respond better to these medications as against inhaled corticosteroids as prophylactic therapy. In children not responding to low dose inhaled corticosteroids, the best add-on therapy is salmeterol, but a small number respond better to Montelukast. In pre-school wheeze, intermittent Montelukast may be an effective strategy in some children who wheeze just with viral colds, but the clinical trial data are controversial. Pre-schoolers with multiple trigger wheeze are probably best treated with inhaled corticosteroids. What is clear is that clinically, a higher proportion of children are prescribed Montelukast than would be predicted from the lterature to respond to the medication. No biomarker to predict response to Montelukast has reached clinical practice, so N of 1 clinical trials should be performed. It is important not to leave children on Montelukast if there is no convincing response to this treatment. © 2014 Elsevier Ltd. Source
News Article | April 12, 2016
The role of biomass in the world energy system looks likely to be constrained, so there will be a need to focus on high value applications where there are few low-carbon alternatives. This is the second of two posts looking at the role of biomass. Here I focus on potential resource constraints. The amount of biomass available to provide energy depends a lot on the amount of land available to grow energy crops, and how much that land can yield. Different assumptions on these variables produce quite different estimates of the total resource, and numerous studies over the years have produced a wide range of results. The amount of waste biomass available also matters, but potential availability from this source is smaller. A comprehensive review of estimates of the biomass resource was carried out two years ago by researchers at Imperial College[i] (see chart). It showed a variation in estimates of a factor of around 40, from of the order of 30 EJ to over 1000 EJ (1EJ =1018 J, or a billion GJ, or 278 TWh). This compares with total world primary energy demand of just under 600 EJ, transport demand of around 100 EJ, and at least 250 EJ to produce present levels of electricity, assuming biomass combustion to remain relatively inefficient[ii]. The authors examine reasons for differences in estimates, which I’ve summarised in the table below. The differences are largely assumption driven, because the small scale of commercial bioenergy at present provides little empirical evidence about the potential for very large scale bioenergy, and future developments in food demand and other factors are inevitably uncertain. Reasons for variation in estimates of total biomass supply In practice there seem to me to be grounds for caution about the scale of the available resource, although all of these propositions require testing, including through implementation of early projects. Small scale to date, despite many years of interest In this context some estimates of the potential for biomass to contribute to energy supply seem optimistic. For example, Shell’s long-term scenarios (Oceans and Mountains) show biomass of 74 EJ and 87 EJ respectively for commercial biomass, 97-133 EJ including traditional biomass by 2060[v]. These totals are towards or above the more cautious estimates for the resource that might ultimately be available (see table above). A recent review article[vi] suggested that by 2100 up to 3.3 GtCp.a. (around 12 billion tonnes of CO ) could be being removed, and producing around 170EJ of energy. However the land requirements for this are very large at about 10% of current agricultural land. The authors suggest instead a mean value for biomass potential of about a third of that, or 60EJ. On balance it seems that biomass is likely to account for at most less than 10% of commercial global energy (likely to be around 800-900EJ by mid-century), and potentially much less if land availability and difficulties with lifecycle emissions prove intractable. It thus seems likely that biomass energy will be relatively scarce, and so potentially of high value. This in turn suggests it is likely to be mainly used in applications where other low carbon alternatives are unavailable. These are not likely to be the same everywhere, but they are likely often to include transport applications, especially aviation and likely heavy trucking, and perhaps to meet seasonal heat demand in northern latitudes. For example, according to Shell’s scenarios aviation (passengers + freight) is expected to account for perhaps 20-25EJ by 2050, and biomass could likely make a useful contribution to decarbonisation in this sector. None of this implies that biomass is unimportant, or has no role to play. It does imply that policies focussing on deploying other renewable energy sources at large scale, including production of low carbon electricity for transport, will be essential to meeting decarbonisation targets. And the optimum use of biomass will require careful monitoring and management. [ii] Data on final consumption and electricity production from Shell and IEA data. 35% efficiency for biomass in electricity is assumed, which is likely to be somewhat optimistic, especially if CCS is employed. [v] http://www.shell.com/energy-and-innovation/the-energy-future/shell-scenarios.html These totals include biofuels, gasified biomass and biomass waste solids, and traditional biomass. [vi] Smith et. al., Biophysical and economic limits to negative CO emissions, Nature Climate Change, January 2016. The paper estimates land requirement for 170 EJ of 380-700 Mha, around 10% of total agricultural land area in 2000 of 4960Mha.
News Article | September 6, 2016
NewsResearchers have created an interactive web tool to estimate the amount of energy that could be generated by wind or solar farms at any location. Contributed Author: Imperial College LondonTopics: Energy/Fuel
Linhares Y.P.L.,Imperial College |
Pavletic S.,U.S. National Cancer Institute |
Gale R.P.,Imperial College London
Bone Marrow Transplantation | Year: 2013
Chronic GVHD (cGVHD) is an important problem after allotransplants. Some risk factors for cGVHD are similar to those of acute GVHD (aGVHD) but others are distinct indicating sometimes overlapping but unique pathogeneses. Precise incidence and prevalence data of cGVHD are lacking because of diverse diagnostic criteria but a 50% risk is a reasonable estimate. Incidence and prevalence of cGVHD are probably growing because of increased use of unrelated donors, blood rather than bone marrow (BM) grafts, decreased early transplant-related mortality (TRM) and increasing frequency of allotransplants. Pathophysiology of cGVHD is complex and poorly understood. Notably, no reliable surrogate end point to predict mechanism(s) of cGVHD has been identified. Therapy of cGVHD is unsatisfactory. Corticosteroids are effective but other drugs are controversial and few are rigorously tested in randomized trials. Highly variable response rates are reported because of small sample sizes and inconsistencies in eligibility, diagnostic and response criteria. We focus on the possible role of immunomodulatory drugs (IMiDs), thalidomide lenalidomide and pomalidomide, in preventing and treating cGVHD. The data suggest activity of thalidomide but at doses not clinically practical in many instances. There are few data with lenalidomide. Trials of pomalidomide, which has immune activities like thalidomide but with fewer adverse effects, are beginning. Because cGVHD is not recently reviewed in Bone Marrow Transplantation, we give a brief background and discuss challenges in diagnosing, understanding and treating cGVHD including the recently proposed National Institutes of Health consensus criteria for cGVHD. © 2013 Macmillan Publishers Limited All rights reserved. Source
News Article | August 23, 2016
The consumption of LSD, short for lysergic acid diethylamide, can produce altered states of consciousness. This can lead to a loss of boundaries between the self and the environment, as might occur in certain psychiatric illnesses. David Nutt, professor of Neuropsychopharmacology at Imperial College, leads a team of researchers who study how this psychedelic substance works in the brain. In this study, Dr. Neiloufar Family, post-doc from the University of Kaiserslautern, investigates how LSD can affect speech and language. She asked ten participants to name a sequence of pictures both under placebo and under the effects of LSD, one week apart. "Results showed that while LSD does not affect reaction times," explains Family, "people under LSD made more mistakes that were similar in meaning to the pictures they saw." For example, when people saw a picture of a car, they would accidentally say"'bus" or "train" more often under LSD than under placebo. This indicates that LSD seems to effect the mind's semantic networks, or how words and concepts are stored in relation to each other. When LSD makes the network activation stronger, more words from the same family of meanings come to mind. The results from this experiment can lead to a better understanding of the neurobiological basis of semantic network activation. "These findings are relevant for the renewed exploration of psychedelic psychotherapy, which are being developed for depression and other mental illnesses. The effects of LSD on language can result in a cascade of associations that allow quicker access to far away concepts stored in the mind," Family explained. The many potential uses of this class of substances are under scientific debate. "Inducing a hyper-associative state may have implications for the enhancement of creativity," Family adds. The increase in activation of semantic networks can lead distant or even subconscious thoughts and concepts to come to the surface. This article was published in the academic journal Language, Cognition and Neuroscience under the title: "Semantic activation in LSD: evidence from picture naming."